Field of the Invention
The present invention relates to a method of processing a wafer in the form of a thin plate with devices formed on a face side thereof by dividing the wafer into chips that carry the individual devices respectively thereon.
Description of the Related Art
Wafers that include a plurality of devices, such as integrated circuits (ICs), large scale integrations (LSIs), power devices formed on a face side thereof in respective areas demarcated by division lines are diced along the division lines and divided into individual device chips by a dividing apparatus such as a laser processing apparatus. The device chips are used in electric devices such as mobile phones, personal computers, or television sets. There have been demands in the art for a technology for reducing the thickness of such device chips with a view to making smaller and lighter mobile phones or wrist watches with a communication function which incorporate those device chips.
One technology that has already been proposed for thinning devices produced by dividing wafers is referred to as dicing before grinding (DBG) (see, for example, Japanese Patent Laid-Open No. 1999-040520). According to the proposed technology, grooves are formed in the face side of a wafer along division lines thereon to a depth corresponding to the finished thickness of device chips, after which a protective member is placed on the face side of the wafer, and then the reverse side of the wafer is ground until the grooves are exposed, whereupon the wafer is divided into individual device chips.